Saturday's 2-1 victory against Sunderland left Albion in seventh spot in the Premier League.
Foster said: "The gaffer keeps reminding us of that and it's a realistic aim.
"Everton losing keeps us right in there. We'll just keep going and now we have our full team back there's no telling where we might go.
"I think we got to the 30-point mark really quickly and then we went five or six without a win.
"Everyone was saying 'that's it, our season's done'. But we have cracked on now, we have players back and we are going in the right direction."